74 research outputs found

    A COMPARISON OF METHODS FOR CALCULATING LACTATE ANAEROBIC THRESHOLDS IN JUDO AND MIXED MARTIAL ARTS ATHLETES

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    The study aimed to determine the differences between exercise intensities at the anaerobic threshold values (VAT) calculated with methods of lactate curve analysis such as LTvisual, LTloglog, LT4.0, LTΔ1, and LTD-max, and to build regression equations that allow athletic training specialists to compare VAT values obtained from LTvisual, LTloglog, LTΔ1, LTD-max with that calculated with LT4.0. The sample analysed during the study consisted of 19 judoka and 22 MMA practitioners in a preparation period for competition. Each of the two disciplines has its own hierarchy of VAT values. The analysis aimed to determine the effect of the athletic discipline factor and of the method factor on VAT values. Results: The coefficient of variation (CV) values obtained indicate that the effective exercise intensities have bigger variation in judoka aerobic endurance training. VAT values assessed for judoka using different methods for analysing the blood lactate concentration curve are more consistent than in MMA competitors. Conclusions: Judo and MMA competitors have their specific hierarchies of running velocities at the anaerobic threshold, with both the athletic discipline factor and the method factor having an interaction effect on the VAT level. VAT levels assessed from the different methods used to analyse the blood lactate concentration curve are more consistent (ANOM) in judoka than in MMA practitioners

    CHARACTER OF RELATIONSHIP BETWEEN SOMATIC COEFFICIENTS AND PHYSIOLOGICAL PARAMETERS THE 15-17 YEAR OLD ICE-HOCKEY PLAYERS

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    The somatic structure in the significant degree determines the possibilities of applying definite tactical solutions, he can limit or stimulate unreeling the competitor individual technique. Somatic conditions can be the limiter of the motor preparation and coordination. The aim of investigations was qualification of dependence between coefficients of the somatic parameters and coefficients of aerobic and anaerobic efficiency. In investigations participated hockey players of National Team Poland in the age from 15 to 17 years. Essential dependences stepped out between the coefficients of aerobic and anaerobic efficiency, and the coefficients of the somatic conditions counted from the value of mass and the length of the body. The number of appointed dependences is higher in hockey players team U18 in the comparison with hockey players team U15

    WORKLOADS OF YOUNG SOCCER PLAYERS

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    The purpose of this study is to present a comparison of the workload demonstrated by young soccer players during the phases of warm-up (WU), first half (FH) and second half (SH) of a league match. Eleven young Polish soccer players took part in this research, playing a league match after completing the WU. During the WU, FH and SH of the match the following variables were recorded: total distance run, maximal and average speed achieved during the runs, number of sprints, distances run in the different speed zones, durations of increased heart rate (HR) in specific ranges, and the maximal, mean and minimal HR. The variables were recorded by means of the Global Positioning System (GPS). The research showed that there were significant differences between the WU, FH and SH in the total distances run (F=30.107, p0.001), the average speed achieved during the runs (F=37.731, p0.001), the distances run at different speeds (p0.001), the duration of increased HR in specific zones, and HRmean (p=0.002) and HRmin (p0.001). Post hoc analysis confirmed that, for the majority of the analyzed parameters, the WU provided a smaller load for the body than did the FH or SH, the intensity of which in some part was higher than that encountered at the anaerobic threshold. In conclusion, it has been shown that the WU and the two halves of the match load the body to varying degrees, the former doing so to a lesser extent than FH or SH

    Predicting Breaststroke and Butterfly Stroke Results in Swimming Based on Olympics History

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    Here we describe historic variations in Olympic breaststroke and butterfly performance and predict swimming results for the 2021 Olympic Games in Tokyo. The results of the finalists, winners, and last participants in the women's and men's finals were analyzed, and a mathematical predictive model was created. The predicted times for the future Olympics were presented. Swimming performance among Olympians has been steadily improving, with record times of 18.51 s for female finalists in the 100 m butterfly (a 24.63% improvement) and 31.33 s for male finalists in the 200 m butterfly (21.44%). The results in all analyzed groups showed improvement in athletic performance, and the gap between the finalists has narrowed. Women Olympians' performances have improved faster than men's, reducing the gap between genders. We conclude that swimming performance among Olympians is continuing to improve

    Calculating lactate anaerobic thresholds in sports involving different endurance preparation

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    AbstractThe aim of this study was to establish the degree of similarity of exercise intensity values at the anaerobic threshold (AT) provided by five methods of lactate curve analysis, i.e., LTAT, LTloglog, 1 mmol AT, 4 mmol AT, and D-max. The pattern of similarities and differences was sought in athletes with varying levels of experience and sports skills, representing two disciplines with different prevailing types of power output during competition: on-road cycling (aerobic metabolism) and ice-hockey (anaerobic metabolism).All groups of athletes tested [Group 1: on-road cyclists (n = 19) at international sporting level (participants of the Olympic Games and World Championships); Group 2: on-road cyclists (n = 20) at national sporting level; Group 3: ice-hockey players (n = 24) at international sporting level (Polish National Team); and Group 4: ice-hockey players (n = 22) at international sporting level (Polish National Team U-20)] performed an incremental exercise.The greatest power values at the anaerobic threshold (PAT) were provided by the LTAT (221.93 ± 34.5 W) and 4 mmol AT (226.38 ± 32.33 W) methods, whereas the lowest were provided by the LTloglog (190.71 ± 25.92 W) method. The PAT produced by the LTloglog method was statistically significantly lower (p ≤ 0.001) than the values provided by LTAT, 4 mmol AT, and Dmax. The PAT levels were found to be statistically significantly different for power values determined using the 4 mmol AT and those produced by the 1 mmol AT (p ≤ 0.001) and D-max (p ≤ 0.01) methods. As shown by the analyses, PAT values vary in the international-level on-road cyclists depending on the method of lactate curve analysis applied

    Corrosion resistance of heat-treated Ni-W alloy coatings

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    The paper presents research on evaluation of corrosion resistance of Ni-W alloy coatings subjected to heat treatment. The corrosion resistance was tested in 5% NaCl solution by the use of potentiodynamic polarization technique and electrochemical impedance spectroscopy. Characteristics of the Ni-W coatings after heat treatment were carried out using scanning electron microscopy, scanning Kelvin probe technique and X-ray di raction. Suggested reasons for the improvement of properties of the heat treated Ni-W coating, obtained at the lowest current density value (125 mA cm2), are the highest tungsten content (c.a. 25 at.%) as well as the smallest and the most homogeneous electrochemically active surface area

    Novel organic material induced by electron beam irradiation for medical application

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    This study analyzed the e ects of irradiation of polytetrafluoroethylene (PTFE) containing 40% of bronze using an electron beam with energy of 10 MeV. Dosages from 26 to156 kGy (2.6–15.6 Mrad) were used. The impact of a high-energy electron beam on the thermal, spectrophotometric, mechanical, and tribological properties was determined, and the results were compared with those obtained for pure PTFE. Thermal properties studies showed that such irradiation caused changes in melting temperature Tm and crystallization temperature Tc, an increase in crystallization heat DHc, and a large increase in crystallinity c proportional to the absorbed dose for both polymers. The addition of bronze decreased the degree of crystallinity of PTFE by twofold. Infrared spectroscopy (FTIR) studies confirmed that the main phenomenon associated with electron beam irradiation was the photodegradation of the polymer chains for both PTFE containing bronze and pure PTFE. This had a direct e ect on the increase in the degree of crystallinity observed in DSC studies. The use of a bronze additive could lead to energy dissipation over the additive particles. An increase in hardness H and Young’s modulus E was also observed. The addition of bronze and the irradiation with an electron beam improved of the operational properties of PTFE

    Effect of 12-Week functional training intervention on the speed of young footballers

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    The aim of the research was to verify the functional state of young football players using selected tests of the Functional Movement Screen (FMS) protocol, as well as the impact of the 12 weeks of functional training on the speed parameters. The research was conducted on 20 highly competitive young (U17) football players. Research project was conducted in two stages: in the first part of the study, the functional assessment was made by using the FMS test, then the measurement of the speed parameters was done with the Microgate photocells system. Results showed a significant improvement in the functional state of young football players: FMS 1 (45.2% of difference, p = 0.004), FMS 2 (24.3% of difference, p = 0.012), FMS 3 (48.5% of difference, p = 0.001). After the functional training program, there was also an improvement in the parameters of the acceleration and velocity: acceleration between 5-10 m and speed between 10-30 m shows significant improvement (expressed during covering a given distance) of the footballers, amounting to 0.02 s (2.4%) and 0.04 s (1.5%). But there was no improvement in acceleration between 0-5 m. An appropriate training schedule, based on FMS results, should be adopted in the annual training program to improve basic motor skills of the football players and minimize their injuries

    Relationship between vertical jump tests and ice-skating performance in junior Polish ice hockey players

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    The aim of this study was to determine the relationships between vertical jumps (VJ) and various on-ice skating performances of junior ice hockey players (n = 19). The three modes of VJ or off-ice measures were countermovement jump with arm swing (CMJ), squat jump (SJ) and depth drop jump (DDJ). The on-ice skating performance was measured by the skating multistage aerobic test (SMAT), forward and backward acceleration test, top speed test, and repeated sprint ability (RSA) test. The relationships between the variables were quantified using Pearson’s product-moment correlation. DDJ showed a significant positive correlation with forward average skating speed (FASS) (r = 0.62) and strong correlations with backward average skating speed (BASS) (r = 0.81), and maximum skating speed (MSS) (r = 0.71). SJ was found to be strongly correlated with BASS (r = 0.82) and MSS (r = 0.76), whereas the only on-ice performance that significantly correlated with CMJ was BASS (r = 0.68). All three modes of VJ were inversely and non-significantly correlated with performance decrement index and fatigue index, as determined by the RSA test. SMAT was not significantly correlated with either VJ or RSA. Correlations between all three modes of VJ tests were significant. Therefore, this study concludes that: (1) DDJ can be used as a predictor of all the ice skating speed tests, whereas SJ can predict BASS and MSS. CMJ, on the other hand, can predict the performance of only BASS. (2) RSA performance cannot be predicted from CMJ, SJ, or DDJ tests, and (3) neither any of the VJ nor RSA can predict skating endurance of junior ice hockey players
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